Decomposition of 2, 6‐diamino‐3, 5‐dinitropyrazine‐1‐oxide (LLM‐105): From thermodynamics to kinetics. Issue 2 (28th September 2020)

• Record Type: Journal Article
• Authors: Hou, Qifeng; Niu, Shiyao; Huang, Can; Wu, Xiaoqing; Qu, Wengang; Zhang, Feng
• Is Part Of: International journal of chemical kinetics. Volume 53:Issue 2(2021)
• Page Start: 242
• Page End: 249
• Publication Date: 2020-09-28
• Subjects: bond order -- chemical kinetic -- intramolecular H‐transfer -- 2, 6‐diamino‐3, 5‐dinitropyrazine‐1‐oxide (LLM‐105) -- potential energy surface; Chemical kinetics -- Periodicals; 541.394
• DOI: 10.1002/kin.21437
• Languages: English
• ISSNs: 0538-8066

Abstract

Abstract: The mechanism of initial decomposition of energetic compound is crucial to understand the heat release efficiency, impact sensitivity, toxic emission, and so on. In the present study, we progressively explored the thermodynamic and kinetic features of the decomposition of LLM‐105, or 2, 6‐diamino‐3, 5‐dinitropyrazine‐1‐oxide, a kind of nitro compound in energetic materials using theoretical calculations. The bond dissociation energies (BDEs), bond orders, and the decomposition pathways were investigated by high‐level quantum chemical calculations, and the temperature‐ and pressure‐dependent rate coefficients were computed by Rice‐Ramsperger‐Kassel‐Marcus (RRKM)/master equation simulations. Although thermodynamic properties, for example, BDEs and bond orders, provide preliminary estimates on a possible decomposition mechanism including trigger bonds with relatively low computational costs, kinetic studies are necessary to determine all reaction pathways and competition relationships among various pathways. The potential energy surface at the theoretical level of DLPNO‐CCSD(T)/CBS//M06‐2X‐D3/6‐311++G(d, p) reveals the complicated decomposition mechanism including the bottlenecks of all channels. The computed rate coefficients showthat the reaction channels yielding NO2 will dominate the initial decomposition at high temperature (>1000 K), while the NO elimination channels play a controlling role at low temperature (<800 K).